Yep - got to love the old guys and their "sky is falling" rhetoric regarding 2.4. They must find it hard to keep up with all the new fandangled stuff available these days - imagine, moving pictures in a box, instant on lighting and a horse drawn buggy without a horse . I have had 2.4 since it was available and have never had an issue with it - IF properly set up. I had a plane once that was playing up a bit in the pit area. All the old timers came over and pointed a stick at the 2.4 and danced around proclaiming that it was evil - there's no antenna poking out the top. Much to their displeasure it turned out being a faulty battery switch. Where i fly there is always somebody proclaiming radio interference for their mishap, problem is it's usually the interference from their brain to their thumbs.
Check batteries - change to 6V if necessary, and just make sure your failsafe is set to idle (turn off the transmitter keeping the plane on and see where the throttle goes to). Have fun and fly.